Process for making a built-up thermal insulating and bituminous waterproofing assembly

ABSTRACT

A built-up bituminous waterproofing and thermal insulation assembly made by the process of placing onto a substrate a plurality of prefabricated, thermal insulating bituminous waterproofing boards adjacent to one another with the edges of the boards being slightly spaced to provide clearances therebetween, sealing the clearances with sealing material and then forming a continuous waterproofing layer over the entire upper surface of the boards and sealing material.

This is a division of application Ser. No. 152,059, filed May 20, 1980.

The present invention relates to thermal insulating and bituminouswaterproofing boards having both a thermal insulating function and awaterproofing function, which boards are suitable for, for example,simultaneously thermally insulating and waterproofing roofs ofbuildings. The present invention also relates to an application processof the thermal insulating and bituminous waterproofing boards. The terms"bitumen" and "bituminous" as used hereinbelow may be replaced by theterm "asphalt".

In many cases, in order to improve the comfortableness of buildings andto prevent damage to buildings caused by changes in temperature, theroofs of buildings are covered with thermal insulating materials.Especially, since the saving of energy resources has been recentlyadvocated in the world, the necessity of the thermal insulation ofbuildings has been strongly promoted due to the fact that the thermalinsulation of buildings remarkably saves the energy used for theair-conditioning of buildings. Various kinds of thermal insulatingmaterials, such as foamed plastic boards and glass fiber boards, are nowused for the thermal insulation of roofs. These thermal insulatingmaterials are generally applied at the time a waterproofing layer isapplied.

Heretofore, the application of thermal insulation to the roofs ofbuildings was carried out either by (a) first placing thermal insulatingmaterials on the roof slabs and then forming a waterproofing layer overthe thermal insulating materials or (b) first forming a waterproofinglayer on the roof slabs and then placing thermal insulating materialsover the waterproofing layer. However, it has been pointed out thatthese processes for applying thermal insulation and waterproofing areaccompanied by the following problems.

(1) Thermal insulating materials have poor mechanical strengths,including compressive strength, impact strength, bending strength andthe like, due to the fact that they have a structure in which a largeamount of gas having a low heat conductivity is included. Therefore, notonly when the thermal insulating materials are placed on either the roofslabs or the top surfaces of waterproofing layers, but also, whenworkers frequently walk on the top of the thermal insulating materiallayers or when the application tools and apparatus are moved ortransferred on site, the applied thermal insulating materials arefrequently damaged. Further, even when the workers walk on the tops ofwaterproofing layers which are applied over the thermal insulatingmaterial layers, and when the application tools and apparatus are movedor transferred on the tops of waterproofing layers, the thermalinsulating materials under the waterproofing layer are liable to bedeformed and damaged, and as a result, the waterproofing layer is alsodamaged. In addition, when a person walks on the tops of roofs where nocover sheet has been applied on waterproofing layers, the thermalinsulating materials and the waterproofing layers mounted thereover areliable to be damaged.

(2) Although various kinds of processes for applying waterproofing ontothe roofs of buildings have been utilized, bituminous waterproofingapplication processes are considered to be the most reliable and aremost widely utilized at present. It is well known that, in accordancewith these bituminous waterproofing application processes, continuousand integral waterproofing layers are formed over the entire surfaces ofthe roofs of buildings by spreading and overlapping several layers ofroofing sheets over the roofs with molten bitumen. In order to protectthe buildings from damage by rain for a long period, such as ten or moreyears, in accordance with the bituminous waterproofing applicationprocesses, it is necessary that the total thickness of the bituminouswaterproofing layer be at least 10 mm in view of the chemical durabilityof bitumen. For obtaining such a thick bituminous waterproofing layer,several roofing sheets are generally spread and overlapped with eachother over a substrate. This spreading and overlapping operation is veryuseful in the bituminous waterproofing application process in order toraise the waterproofing function. However, since this operation involvesmany steps and, further, the spreading step of the thermal insulatingmaterial is added in the case of the combined application process ofthermal insulation and built-up waterproofing, the operation becomestroublesome.

In addition, since foamed thermoplastic materials, which are preferablethermal insulating materials, have a poor heat resistance, they have theserious problem of easily suffering fatal damage due to the heat ofmolten bitumen when the foamed thermoplastic materials are applied incombination with bituminous roofing or waterproofing.

Accordingly, the main objects of the present invention are to obviatethe aforementioned problems associated with the conventional combinedapplication processes of thermal insulation and built-up waterproofingand to provide novel thermal insulating and waterproofing boards whichare capable of being easily applied to a substrate, and are capable offacilitating the combined application processes of thermal insulationand built-up waterproofing.

Another object of the present invention is to provide a novel combinedapplication process of thermal insulation and built-up waterproofing.

In accordance with the present invention, there is provided a thermalinsulating and bituminous waterproofing board comprising:

(i) a modified bitumen layer containing, as a principal constituent, amixture of bitumen and at least one inorganic filler, which layer isformed in the form of a thick board;

(ii) a flat sheet laminated on each surface of the modified bitumenlayer, said flat sheet consisting of a fibrous sheet, and;

(iii) a thermal insulating material layer bonded, through the flatsheet, to one surface of the modified bitumen layer.

In accordance with the present invention, there is also provided acombined application process for manufacturing a built-up bituminousroofing or waterproofing and thermal insulating assembly comprising thesteps of:

(a) placing thermal insulating and bituminous waterproofing boardscomprising (i) a modified bitumen layer containing, as a principalconstituent, a mixture of bitumen and at least one inorganic filler andformed in the form of a thick board, (ii) a flat sheet laminated on eachsurface of the modified bitumen layer, said flat sheet consisting of afibrous sheet, and (iii) a thermal insulating material layer bonded,through the flat sheet, to one surface of the modified bitumen layer,onto a substrate surface in such a manner that the thermal insulatinglayer of the board is in close adhering contact with the substratesurface;

(b) sealing the clearances between said boards with sealing material;and then,

(c) forming a continuous and integral waterproofing layer over theentire surface of the placed boards.

The present invention will now be explained in detail with reference tothe accompanying drawings, illustrating the preferred embodiments of thepresent invention. However, the present invention is not limited tothese preferred embodiments.

FIG. 1 is an explanatory cross-sectional view illustrating the basicstructure of the board according to the present invention.

FIGS. 2 and 3 are explanatory cross-sectional views illustrating thestructures of two preferred embodiments of the board according to thepresent invention.

FIG. 4 is an explanatory schematic view illustrating the foaming processof the rigid polyurethane foam, when the rigid polyurethane foam is usedas a thermal insulating material of the board according to the presentinvention.

FIGS. 5 and 6 are explanatory cross-sectional views illustrating thestructures of two other preferred embodiments of the board according tothe present invention.

FIG. 7 is an explanatory schematic view illustrating the combinedapplication process of thermal insulation and built-up waterproofingaccording to the present invention.

As illustrated in FIG. 1, the thermal insulating and bituminouswaterproofing board 10 basically comprises: a modified bitumen layer 11which is formed in the form of a relatively thick board from a bitumenmixture containing, as a principal constituent, a mixture of bitumen andan inorganic filler or fillers; flat sheets 12 and 13 laminated on bothsurfaces of the modified bitumen layer 11, and; a thermal insulatingmaterial layer 14 bonded to the flat sheet 13. The flat sheets 12 and 13consist of a fibrous sheet.

Thus, the thermal insulating and bituminous waterproofing boardaccording to the present invention comprises the modified bitumen layerhaving, on each surface thereof, the laminated flat sheet consisting ofa fibrous sheet and the thermal insulating material layer. The modifiedbitumen layer is sometimes referred to as a bituminous waterproofingboard hereinbelow. The bituminous waterproofing board has a function ofpreventing the underlying thermal insulating material from beingdestroyed and, also, serves as a waterproofing layer. Therefore, it isnecessary that the material from which the bitumen waterproofing boardis formed have high mechanical strengths, such as compressive strength,impact strength, bending strength and the like, and also, have a highwaterproofing property. A board which is formed from only bitumen is notpreferable, since stable high mechanical strengths cannot be obtainedover a wide range of temperature. Surprisingly, the present inventor hasfound that both good mechanical strengths and a high waterproofingproperty can be obtained in the case where a bitumen mixture mainlycontaining bitumen and an inorganic filler is formed into a relativelythick board.

The inorganic fillers which are incorporated into the bitumen mixtureinclude, for example, conventional inorganic fillers in the form ofpowder, granules or flakes, such as calcium carbonate, clay, talc,aluminum hydroxide, mica, silica, graphite, carbon black and the like;mineral granules, such as fine and coarse sand, fine gravel, finelycrushed stone and the like, and; inorganic fibers, such as asbestos,glass fibers, rock wool and the like. These inorganic fillers can beused alone or in any mixture thereof. The kinds and the porosity of theinorganic fillers to be used in the present invention are preferablyselected from the aforementioned inorganic fillers in such a manner thata good filling of the fillers into the bitumen mixture can be obtained.Especially, fibrous inorganic fillers can be advantageously usedtogether with the other inorganic fillers.

Although the amount of the inorganic filler to be incorporated into thebitumen mixture may be varied over a wide range, it is generally withinthe range of from about 20 to about 90% by weight, based on the totalweight of the bitumen mixture. From the point of view of the mechanicalstrength, the waterproofing property and the processibility, the amountof the inorganic filler to be incorporated into the bitumen mixture ispreferably within the range of from 50 to 90% by weight, more preferably70% or more, based on the total weight of the bitumen mixture. The mostpreferable composition of the bitumen mixture is as follows.

    ______________________________________                                        Composition      % by weight                                                  ______________________________________                                        Blown bitumen    25                                                           Asbestos         20                                                           Talc             22                                                           Calcium Carbonate                                                                              33                                                           ______________________________________                                    

Although organic fillers may be also used in the present invention, theuse of organic fillers is not generally recommendable in view of theirwater resistance, the dimensional stability and the heat resistance.

The bitumen mixture used in the present invention can be prepared byuniformly mixing the inorganic filler(s) with molten bitumen in, forexample, a ribbon blender, a kneader blender, a Banbury mixer, anextruder, a mixing roll and the like. Natural or synthetic rubbers canbe optionally added in order to improve the low temperature propertiesof the bitumen. Other additives such as surface active agents can bealso added to improve the dispersibility of the fillers. The bitumenmixture thus prepared can be easily formed in the form of a board byusing, for example, heated rolls or an extruder. However, in order tofurther improve the processibility as well as the mechanical strengthand the dimensional stability of the product, flat sheets, essentiallyconsisting of a fibrous material, are preferably laminated onto bothsurfaces of the bitumen mixture board (i.e. the modified bitumen layer)during the shaping step.

The fibrous sheets used in the present invention include, for example,woven or non-woven fabric made of glass fibers, asbestos fibers, varioussynthetic fibers and the like. Especially, non-woven fabric of glassfibers and glass mesh (woven fabric) are effective for improving thedimensional stability of the product. In the case where the bituminouswaterproofing board is formed by using heated pressure rolls, twofibrous sheets are directly fed into the roll clearance in such a mannerthat the rolls are wrapped with the fibrous sheets, and then, thebitumen mixture containing bitumen and the inorganic filler(s) is fedand pressed between the fibrous sheets, to thereby form a bituminouswaterproofing board comprising the bitumen mixture board having thelaminated fibrous sheets on both surfaces thereof. On the other hand, inthe case where the bituminous waterproofing board is formed by using anextruder, a flat sheet, can be laminated onto each of the two surfacesof the extruded bitumen mixture in the form of a board by using pressrolls immediately after the bitumen mixture is extruded. The weight ofthe fibrous sheet is preferably at least about 30 g/m² from the point ofview of the processability and the properties of the product (e.g.dimensional stability, compression strength, impact strength and bendingstrength). Fibrous sheets which are previously impregnated with bitumencan be advantageously used. However, in the case where fibrous sheets,such as non-woven glass fabric, into which bitumen easily permeates areused, it is not necessary that the fibrous sheets be previously treatedwith bitumen. This is because the bitumen contained in the bitumenmixture permeates into the fibrous sheets when the fibrous sheets arelaminated onto the bituminous waterproofing board between the rolls. Inthe case where the permeation of the bitumen into the fibrous sheets isinsufficient or where a bitumen coated layer 16 is laminated on the flatsheet 12 on top of the modified bitumen layer 11, as illustrated inFIGS. 2 and 3, molten bitumen can be coated onto the flat sheets 12 and13 or the flat sheet 12 by means of a roll coater, a knife coater, orthe like, immediately after the above-mentioned pressure lamination stepof the bituminous waterproofing board. Thus, the water resistance of theproduct can be further improved by the permeation of bitumen into theflat sheets 12 and 13.

Furthermore, in a thermal insulating and bituminous waterproofing board15 or 15', as illustrated in FIGS. 2 and 3, when a bitumen or rubberizedbitumen coated layer 16 is coated onto the top surface of the flat sheet12 onto which the thermal insulating material 14 is not laminated, notonly is the waterproofing property of the product increased, but also,the coated layer 16 can advantageously be a surface for forming awaterproofing layer because of the adhesion properties of the coatedlayer 16. The rubberized bitumen contains bitumen, rubbers andoptionally, tackifiers, softeners and the like. Although bitumen orrubberized bitumen may be coated onto the surface of the flat sheet 13on which the thermal insulating material is laminated, generally, theinsulating material layer can be advantageously adhered when the bitumenor rubberized bitumen layer is not placed on the surface of the flatsheet 13.

The rubberized bitumen is a bitumen which has been modified to imparthigh tackiness at an ambient temperature thereto by blending, mainly,natural or synthetic rubber and/or natural or synthetic resin intobitumen. The rubberized bitumen generally contains approximately 5through 95% by weight of bitumen and approximately 5 through 95% byweight of rubber, and/or resin, and preferably, contains 20 through 90%by weight of bitumen and 10 through 70% by weight of rubber, and/orresin. In the case where the content of the bitumen is less thanapproximately 5% by weight, the affinity of the rubberized bitumen to,for example, a bituminous waterproofing membrane becomes unpreferablypoor. Contrary to this, if the content of the rubber and/or resin isless than approximately 5% by weight, the flexibility and expandabilityof the rubberized bitumen at a low temperature becomes unpreferablypoor.

The rubbers employed in the preparation of the rubberized bitumeninclude vulcanized or unvulcanized rubber or reclaimed rubber, forexample, natural rubber, and synthetic rubber, such as styrene-butadienerubber (SBR), acrylonitrile-butadiene rubber (NBR), chloroprene rubber(CR), butadiene rubber (BR), isoprene rubber (IR), butyl rubber ((IIR),ethylene-propylene rubber (EPR), ethylene-propylene diene mar (EPDM),polyisobutylene (PIB), styrene-butadiene-styrene block copolymer,styrene-isoprene-styrene block copolymer, chlorinated polyethylene,ethylene-vinyl acetate copolymer and the like. These rubbers can be usedalone or in any mixture thereof.

The resins employed, alone or together with the rubber, in thepreparation of the rubberized bitumen include, for example, naturalresins, such as rosin or its derivatives (e.g. estergum), tall oil,cumarone-indene resin; synthetic resins, such as various petroleumresins or polyolefins (e.g. polybutene), and the like. These resins canbe used alone or in any mixture thereof. If necessary, a portion ofthese rubber and/or resin components (up to 50% by weight) can bereplaced by softeners, such as animal and vegetable oils and fats,mineral oils, and the like, to further increase the tackiness of thebitumen.

In order to prevent an unpreferable blocking phenomenon which can occurduring production, storage and transportation of the board according tothe present invention, the top surface of the bitumen or rubberizedbitumen coated layer 16 can be preferably covered with a layer 17 ofmineral granules, powder or flakes, such as calcium carbonate, clay,talc, mica, silica powder, and the like (see FIG. 2), or a plastic filmor release sheet 18 (see FIG. 3), and the like. Especially when awaterproofing layer is applied onto the thermal insulating andbituminous waterproofing board according to the present invention byusing a so-called cold application process (that is, an applicationprocess wherein a waterproofing layer is formed without using moltenbitumen on an application site), it is preferable to laminate thebitumen or rubberized bitumen coated layer 16 on the flat sheet 12 and,then, to cover the layer 16 with the release sheet 18 is illustrated inFIG. 3. This is because, since the board can be easily applied, at theapplication site, upon the removal of the release sheet from the board,and since good adhesion properties can be obtained due to the presenceof the bitumen or rubberized bitumen layer, the application process ofthe present invention is remarkably facilitated compared to theconventional processes.

The thickness of the bituminous waterproofing board may be varied over awide range, but will generally be in the range of from 2 to 25 mm and,preferably, in the range of from 5 to 10 mm. The size of the bituminouswaterproofing boards can be any size depending upon the purpose of theiruse. For example, they can be 1 m length×1 m width, 1 m length×0.5 mwidth, or the like.

The thermal insulating layer 14 is laminated on one surface of thebituminous waterproofing board. The thermal insulating layer 14 can becomposed of any conventional thermal insulating materials. Examples ofsuch thermal insulating materials are inorganic thermal insulatingboards made of, for example, rock wools, slag wools, asbestos, glassfibers, calcium silicate, perlite, vermiculite, gypsum, foamed glassesand the like; foamed synthetic resins made of, for example, polystyrene,polyethylene, acrlylic resin, phenol resin, urea resin, epoxy resin,diallylphthalate resin, urethane resin and the like; foamed rubbers,wood chip boards, wood wool boards and the like. The thickness of thethermal insulating material layer 14 may be varied over a wide range andis appropriately determined depending on the required heat transmissionresistance.

In order to laminate the thermal insulating material layer 14 onto thebituminous waterproofing board, a bituminous waterproofing board and athermal insulating board having the same size may be bonded to eachother by using bitumen, rubberized bitumen, conventional adhesives andthe like. However, from the point of view of the production of thethermal insulating and bituminous waterproofing board according to thepresent invention, preferable thermal insulating materials are thosesuch as rigid polyurethane foam, which can be directly foamed on thesurface of the bituminous waterproofing board to form a foamed layer.Thus, the bonding step of the bituminous waterproofing board and thethermal insulating board, and the use of adhesives, can be preferablyobviated.

One example of the process of laminating a thermal insulating materiallayer of a rigid polyurethane foam onto a bituminous waterproofing boardwill now be explained with reference to FIG. 4.

As illustrated in FIG. 4, the bituminous waterproofing boards 19 whichhave been formed in a previous bituminous waterproofing board formingstep (not shown) are placed on a conveyor belt 20 in such a manner thatthe surface thereof, onto which a thermal insulating material layer isto be laminated, faces upwards. The surface on which a thermalinsulating material layer is to be formed has no bitumen or rubberizedbitumen coating. The boards 19 are transported on the conveyor belt 20.The bituminous waterproofing board 19 comprising the flat sheet 13consisting essentially of the fibrous sheet is preferably impregnated,in the production step of the board 19, with bitumen in asemi-impregnated state sufficient to bond the modified bitumen layer 11to the flat sheet 13. That is to say, the flat sheet 13 is preferablyimpregnated with bitumen in such a manner that the bitumen contained inthe modified bitumen does not exude to the opposite surface of the flatsheet 13, but slightly permeates into the fibrous sheet. This isbecause, in the case where the bitumen exudes to the opposite surface ofthe flat sheet 13, the bonding of the polyurethane foam and thebituminous waterproofing board is likely to be adversely affected. Thepermeation extent of the bitumen can be easily controlled by, forexample, the bitumen content of the modified bitumen, the workingtemperature, the pressure of pressure rolls and the like.

On the other hand, when thermal insulating materials which are formed ina separate step, such as foamed polystyrene resins, glass fiber boards,foamed glasses, and the like, are used, it is preferable that the flatsheet 13 be completely impregnated with bitumen, prior to the bonding ofthe bituminous waterproofing boards and the thermal insulatingmaterials, to prevent the generation of air spaces in the flat sheet 13.This is because the presence of air spaces in the flat sheet 13 causesthe permeation of water into the flat sheet 13 from the end thereof dueto capillary action.

The bituminous waterproofing boards 19 are previously cut intopredetermined size and, then, transferred onto the conveyor belt 20.Onto the upper surface of the bituminous waterproofing board 19 placedon the belt conveyor 20, raw liquid material 21 for foaming rigidpolyurethane foam, which is previously prepared, is coated through anappropriate nozzle 22. The raw liquid material 21 is covered with a flatsheet (e.g. a non-woven glass fabric) 23 which is guided by a beltconveyor 25 and, then, fed to a foaming step. Since bitumen does notexude onto the surface of the flat sheet of the bituminous waterproofingboard 19, on which surface the raw liquid material 21 is to be coated,the urethane foaming liquid penetrates into the flat sheet and, thus, avery strong bond between the bituminous waterproofing board 19 and thefoamed layer through the flat sheet 13 can be effected after theurethane is cured. It should be noted that any of the fibrous sheetsexemplified above as a flat sheet for the bituminous waterproofingboards can be used as the above-mentioned flat sheet for the foamedlayer instead of the non-woven glass fabric. Although the use of theflat sheet for the foamed layer is not essential, this flat sheet can bepreferably and advantageously used to give a good dimensional stabilityto the product. In order to improve the water resistance of the productand the bonding properties of the product to the application substrate,the flat sheet can be also impregnated with bitumen, atacticpolypropylene and the like, or coated with rubberized bitumen. However,it is preferable that the surface of the flat sheet which is to be incontact with the urethane foaming liquid be in such a state that theurethane foaming liquid can easily permeate into the flat sheet.

The bituminous waterproofing board 19 having the urethane foaming liquid21 and the non-woven glass fabric 23 thereon is fed to the foaming stepand the foamed layer 24 is formed in a conventional manner. Thethickness of the foamed layer 24 can be optionally controlled to anydesired value by adjusting the clearance between the conveyor belts 20and 25. The thermal insulating and bituminous waterproofing board thusproduced is cut to the size of the bituminous waterproofing board 19 ata cutting step 26.

Although the manufacturing process of the thermal insulating andbituminous waterproofing boards, wherein foamed polyurethane is used asa thermal insulating layer, has been illustrated hereinabove, it shouldbe noted that the bituminous waterproofing boards and any formed thermalinsulating boards can be laminated with each other by using anyconventional adhesives in a known manner.

FIGS. 5 and 6 are cross-sectional views illustrating other embodiments30 and 30' of the thermal insulating and waterproofing boards accordingto the present invention.

In the embodiment illustrated in FIG. 5, a flat sheet 27, comprising afibrous sheet similar to the flat sheets 12 and 13, is laminated to thebottom surface of the thermal insulating layer 14. This flat sheet 27improves the dimensional stability of the product and the bondingproperties of the product to the substrate. Although only the flat sheet12 is laminated on the top surface of the compound bitumen layer 11 inthe board 30 illustrated in FIG. 5, the bitumen or rubberized bitumencoated layer 16 and the mineral granule layer 17 or the release sheet 18can be laminated on or over the top surface of the compound bitumenlayer 11, as illustrated in FIGS. 2 and 3.

In the thermal insulating and bituminous waterproofing board 30'illustrated in FIG. 6, a bitumen or rubberized bitumen coated layer 28is laminated, via the flat sheet 27, on the bottom surface of thethermal insulating layer 14. This coated layer 28 enhances the waterresistance and the moisture resistance of the product and improves theapplication properties of the product to the substrate. Any conventionalrelease sheet 29 is laminated to the bottom surface of the coated layer28, to thereby prevent the blocking of the product during themanufacturing process as well as during the storing and transferringstages. The release sheet 29 is removed from the coated layer 28 beforethe board 30' is used at construction site. In the embodimentillustrated in FIG. 6, one or both of the release sheets 18 and 29 maybe replaced with the mineral granule or powder layer 17 illustrated inFIG. 2.

The combined application process for manufacturing a built-up bituminouswaterproofing and thermal insulating assembly at a construction siteaccording to the present invention will now be illustrated withreference to the accompanying FIG. 7.

As illustrated in FIG. 7, thermal insulating and bituminouswaterproofing boards 34 of the present invention, which compriseintegrally bonded bituminous waterproofing boards 32 and thermalinsulating boards 33, are laid over a substrate 31. The boards 34 arebonded to the substrate 31 by an adhesive (the reference numeral 35 isan adhesive layer). Then, sealing materials 36 are applied onto theclearances between adjacent thermal insulating and bituminouswaterproofing boards 34, whereby the clearances are sealed and, over thesealed boards, a waterproofing layer 37 is formed. The thermalinsulating and waterproofing layer thus formed may optionally be coveredwith concrete.

Bituminous adhesives, such as molten bitumen, bituminous cement,rubberized bitumen and the like, can be advantageously used for bondingthe thermal insulating and bituminous waterproofing boards 34 to thesubstrate 31. Although conventional solvent type or emulsion typeadhesives made from synthetic rubbers and synthetic resins can be alsoused, depending upon the type of thermal insulating boards 33, it ispreferable to use adhesives having an appropriate fluidity at anordinary ambient temperature or less, which fluidity is similar to thatof the bituminous adhesives. In the case where a board 30' having theself-adhesive coated layer 28 on the bottom of the thermal insulatingboards 14, as illustrated in FIG. 6, is used, the board 30' can beeasily bonded to the substrate by simply removing the release sheet 29from the board 30' and then pressing the board 30' to the substrate.

The thermal insulating and bituminous waterproofing boards 34 can beapplied onto a conventional moistureproof layer by using the abovementioned adhesives after the moistureproof layer is installed on thesubstrate. Particularly, there can be advantageously bonded to thesubstrate, a moistureproof layer of a self-adhesive sheet comprising:(i) a base sheet, such as a woven or non-woven fabric made from asynthetic fiber (e.g. polyester fiber, polyvinyl alcohol fiber,polyamide fiber or the like); (ii) rubberized bitumen coated layers onboth sides of the base sheet, which are formed by coating theabove-mentioned rubberized bitumen onto the both surfaces of the basesheet, and; (iii) release sheets, releasably laminated on the bothcoated layers. Accordingly, the thermal insulating and bituminouswaterproofing board of the present invention can be preferably appliedonto the moistureproof layer by utilizing the self-adhesive property ofthe self-adhesive sheet without using hot molten bitumen (i.e. a coldapplication process), and the formation of the moistureproof layer andthe bonding of the thermal insulating and bituminous waterproofing boardcan be simultaneously effected.

After the application of the thermal insulating and bituminouswaterproofing boards, the joint clearances between the adjacent boardsare sealed by using the sealing materials 36. Non-shaped sealingmaterials and shaped sealing materials, such as sealing materials in theform of, for example, tape, string and the like, can be used, as thesealing material 36, alone or in any combination thereof. Preferablesealing materials which are used, as the sealing material 36, in thepresent application process are those which have a good adhesiveness tothe thermal insulating and bituminous waterproofing board 34, and also,which have an appropriate fluidity, so that the sealing material 36 isnot broken at the joints due to repeated stress which is derived fromexpansion and contraction of the boards themselves caused by increasesand decreases of the ambient temperature. Any sealing materials whichsatisfy the two requirements mentioned above can be used in theapplication process of the present invention. Particularly, theabove-mentioned rubberized bitumen type sealing materials can bepreferably used in the present invention. Although the rubberizedbitumen can be used in the non-shaped form, it is particularlyadvantageous to use rubberized bitumen type sealing materials in theform of tape which is prepared by: (i) coating the above-mentionedrubberized bitumen having a high self-adhesiveness, at a thickness ofapproximately 0.2 to 2 mm, on both surfaces of the base sheet, such aswoven or non-woven fabric made from synthetic fibers, plastic films,rubber or plastic sheets; (ii) releasably laminating the release sheetson the surfaces of the coated rubberized bitumen layers; (iii) cuttingthe product thus obtained into tapes having a width of approximately 10to 30 cm, and; (iv) rolling the tapes into a rolled product. When saidsealing materials in the form of tape are used at the construction site,the rubberized bitumen sealing tape can be bonded to the joint portionsof the boards 34 at an ordinary ambient temperature without using moltenbitumen (i.e. a so-called cold application process), while the releasesheets are removed from the sealing tape by manually peeling the releasesheets therefrom. Thus, according to this embodiment of the presentinvention, the application operations at construction site can beperformed under extremely high safety conditions, due to the facts thatneither hot molten bitumen nor organic solvents are used at theconstruction site, and uniform sealing can be effected by the use of thepre-shaped sealing materials.

Particularly, in the conventional application processes, when awaterproofing layer is formed on the top surface of the substrates inthe form of boards, the waterproofing layer at the joint portions of thesubstrates is likely to be locally broken at the joint portions due tofatigue of the substrates, which fatigue is the result of expansion andcontraction of the substrates themselves caused by increases anddecreases of temperature. Contrary to this, according to the presentinvention, since the sealing materials comprising the above-mentionedrubberized bitumen having an appropriate plastic fluidity even at anordinary ambient temperature or less are used, a substantial portion ofthe external force which is derived from expansion and contraction ofthe thermal insulating and bituminous waterproofing boards at the jointsportions thereof is absorbed into the sealing material (i.e. therubberized bitumen). Thus, local breaks in the waterproofing layer canbe effectively obviated. Furthermore, there can be used as the sealingmaterial 36, one-surface adhesive type sealing tapes comprising: (i) abase sheet, such as kraft paper and plastic sheet, only one surface ofwhich is subjected to a releasing treatment by using, for example,silicone resins, fluorine resins or the like, in a conventional manner,and; (ii) a rubberized bitumen layer, having a thickness ofapproximately 0.2 to 2 mm, coated on the non-release surface of the basesheet. The one-surface adhesive type sealing tapes usually have a widthof approximately 10 to 30 cm and are in the form of a roll. In the casewhere this sealing tape is used for sealing the joint portions of theadjacent thermal insulating and bituminous waterproofing board 34, thewaterproofing layer 37 applied over the sealing tape 36 is not bonded tothe sealing tape, due to the fact that the upper surface of the sealingtape is not subjected to the release treatment. Therefore, even when theexpansion and contraction of the boards 34 occur at the joint portionsthereof, the external force which is derived from such expansion andcontraction can be not only relaxed by the cold flow of the rubberizedbitumen of the sealing tape, but also, dispersed by the relative slidebetween the release surface of the sealing tape 36 and the waterproofinglayer 37. Thus, breaks in the waterproofing layer 37, which is a seriousproblem in the conventional application process, can be completelyobviated.

After sealing the joint portions between the thermal insulating andbituminous waterproofing boards 34 by the sealing materials 36, thewaterproofing layer 37 is formed over the sealed boards 34. However, thebituminous waterproofing layers 32 of the boards 34 have a sufficientwaterproofing property by themselves, and accordingly, even when thewaterproofing layer 37 is not formed, sufficient thermal insulating andwaterproofing properties are provided, so long as the joint portions ofthe boards are reliably sealed in the manner mentioned above.Nevertheless, in order to provide more stable and high waterproofingfunctions over a long period of time, it is preferable to form thewaterproofing layer 37 over the sealed boards 34. In the case where thewaterproofing layer 37 is not covered with, for example, concrete, a capsheet is bonded to the uppermost layer to present a good appearance.

The waterproofing layer 37 can be formed by coating liquid or semi-solidwaterproofing materials (i.e. so-called coating waterproof materials),or by laminating one or more roofing sheets on the substrate (i.e. thesealed boards 34). The roofing sheets include, for example, conventionalbituminous roofing sheets, synthetic polymer roofing sheets made from,mainly, synthetic rubbers or synthetic resins and the like. Theseroofing sheets can be used in any combination thereof when plural layersare laminated. The use of the bituminous roofing sheets is mostpreferable.

The fabrication of the waterproofing layer can be carried out by eitherconventional hot application processes or conventional cold applicationprocesses. In the case where the first waterproofing layer is formed bya cold application process, the thermal insulating and bituminouswaterproofing board having a bitumen or rubberized bitumen coated layerand a release sheet on the surface thereof, as illustrated in FIGS. 3and 6, is used. The roofing sheet can be bonded to the bitumen orrubberized bitumen coated layer, while the release sheet is removed atthe construction site. In the case of a hot application process, thethermal insulating and bituminous waterproofing board having a mineralgranule or powder layer on the surface thereof, as illustrated in FIG.2, can also be used.

Alternatively, the waterproofing layer can be formed by using abituminous roofing sheet having, on the surface thereof, anapproximately 1 to 3 mm width of a bitumen coated layer in the followingmanner. That is to say, while the bitumen coated layer is heated bymeans of any portable heating device, such as a burner, a torch lamp ora hot-air device, to thereby soften or melt the bitumen, the bitumencoated layer is bonded to the thermal insulating and bituminouswaterproofing board. In this case, although a board having, on thesurface thereof, the bitumen or rubberized bitumen coated layer coveredwith a release sheet, as illustrated in FIG. 3, can be advantageouslyused, a board having, on the surface thereof, a mineral granule orpowder layer, or a mineral flake layer, as illustrated in FIG. 2, can beused. When the roofing sheet is bonded to the board, the top surface ofthe board can also be heated by means of said portable heating device,without causing any damage to the lower thermal insulating material.

The application of the roofing sheets over the surfaces of the thermalinsulating and bituminous waterproofing board can be carried outaccording to any conventional roofing application process. However, theroofing sheets are preferably laid over the sealed boards in such amanner that the joint portions of the sealed boards and those of thefirst roofing layers do not overlap.

As described in detail above, according to the present invention, thefollowing practical advantages are presented.

(1) Since the thermal insulating and bituminous waterproofing board ofthe present invention comprises the bituminous waterproofing boardhaving high mechanical strengths, including compression strength, impactstrength and bending strength, which board is laminated on the topsurface of the thermal insulating layer, the damage problems due tobreaks in the thermal insulating material in the prior art can beeffectively obviated and, therefore, a complete thermal insulating andwaterproofing layer can be obtained at a high operational efficiency andwith a very low material loss.

(2) Since the above-mentioned bituminous waterproofing board has a highwaterproofing property by itself, a thermal insulating and waterproofinglayer having sufficient thermal insulating and waterproofing propertiescan be easily formed by applying only one roofing sheet onto the board,so long as the joint portions of the boards are reliably sealed. Thus, aremarkable labor-saving thermal insulating and waterproofing applicationprocess can be established, and a thermal insulating and waterproofinglayer having more uniform thermal insulating and waterproofingproperties than in the prior art can be safely obtained.

(3) Foamed materials, such as foamed polyethylene, foamed polystyreneand the like, which are readily available at a low cost but have arelatively low heat resistance, are difficult to use, as a thermalinsulating material, in the case where a waterproofing layer is formedaccording to a hot application process. However, these thermalinsulating materials can be used in the present application process, asmentioned above.

(4) Since the thermal insulating and waterproofing boards of the presentinvention are manufactured under well-controlled constant conditions atthe factory, products having a constant quality can be produced, and areliable thermal insulating and waterproofing layer can be easilyobtained by simply laying the pre-fabricated boards, having a constantquality, over the substrate at the construction site. Thus, according tothe present invention, the finish of the applied thermal insulating andwaterproofing layer does not depend on the skill of the workers on site,whereas the finish largely depends on the skill of the workers in theconventional application processes.

(5) Since a large amount of the inorganic filler is contained in thethermal insulating and waterproofing board of the present invention, theamount of bitumen required for obtaining a waterproofing layer havingthe same waterproofing function as that of the conventionalwaterproofing layer can be remarkably reduced.

I claim:
 1. A process for making a built-up bituminous waterproofing andthermal insulation assembly, comprising the steps of:(a) placing ontothe surface of a substrate a plurality of prefabricated, thermalinsulating and bituminous waterproofing boards, each consistingessentially of (i) a thermal insulating layer having an upper surfaceand a lower surface, said thermal insulating layer being made of thermalinsulating material; (ii) a first, flat, fibrous sheet having an uppersurface and a lower surface, the lower surface of said first sheet beingbonded to the upper surface of said thermal insulating layer in direct,face-to-face, mutually adhering contact; (iii) a modified bitumen layerhaving a thickness within the range of from 2 to 25 mm and having anupper surface and a lower surface, said modified bitumen layerconsisting essentially of a uniform mixture of waterproofing bitumen and50% to 90% by weight, based on the total weight of the mixture, ofpieces of at least one inorganic filler, the lower surface of saidmodified bitumen layer being bonded to the upper surface of said firstsheet in direct, face-to-face, mutually adhering contact; and (iv) asecond, flat, fibrous sheet having an upper surface and a lower surface,the lower surface of said second sheet being bonded to the upper surfaceof said modified bitumen layer in direct, face-to-face, mutuallyadhering contact, said boards being placed onto the substrate surfaceadjacent to one another with the edges of said boards being slightlyspaced to provide clearances therebetween, said boards forming a layeron said substrate surface with the thermal insulating layer of each ofsaid boards being in close adhering contact with said substrate surface;(b) then sealing the clearances between said boards with sealingmaterial; and (c) then forming a continuous, waterproofing layer overthe entire upper surface of said boards and said sealing material, saidwaterproofing layer being integral therewith.
 2. A process as claimed inclaim 1, wherein said waterproofing layer is formed by using one or moreroofing sheets.
 3. A process as claimed in claim 1, wherein saidprefabricated boards are each adhered onto said substrate surface byhumidityproof adhesive sheets interposed between said substrate surfaceand said boards, said adhesive sheets having rubberized bitumen layershaving high adhesiveness on the upper and lower faces thereof.
 4. Aprocess as claimed in claim 1, wherein said sealing material is asealing tape comprising (i) a fibrous base sheet; and (ii) a pair ofrubberized bitumen coating layers having high adhesiveness laminatedonto the upper and lower surfaces, respectively, of said base sheet, oneof said layers (ii) being placed in direct, face-to-face, mutuallyadhering contact with at least two adjacent boards.
 5. A process asclaimed in claim 1, wherein said sealing material is a sealing tapecomprising (i) a release sheet having a releasable upper surface and anon-releasable lower surface, said upper surface of said release sheetbeing releasable relative to said waterproofing layer and not adheredthereto, and (ii) a rubberized bitumen layer having high adhesivenessand having an upper surface and a lower surface, said upper surface ofsaid rubberized bitumen layer being adhesively secured to said lowersurface of said release sheet and the lower surface of said rubberizedbitumen layer being adhesively secured to at least two adjacent boards.6. A process as claimed in claim 1, wherein said continuous and integralwaterproofing layer is formed by placing bituminous roofing sheets ontothe upper surfaces of said adjacent boards in direct, face-to-facecontact therewith, each of said bituminous roofing sheets comprising athick bitumen layer, and heating said roofing sheets thereby to softensaid thick bitumen layers to bond same to said boards whereby to formsaid continuous waterproofing layer which is integral with said boards.7. A process as claimed in claim 6, wherein said bituminous roofingsheets each further comprise a mineral layer made of a material selectedfrom the group consisting of mineral granules, mineral powder andmineral flakes, said mineral layer being applied on top of said thickbitumen layer, said mineral layer being the uppermost layer of saidassembly.
 8. A process as claimed in claim 6, wherein said thick bitumenlayer is from 1 to 3 mm thick.
 9. A process as claimed in claim 6,wherein said bituminous roofing sheets each further comprise a releasesheet in direct, face-to-face contact with said thick bitumen layer, andcomprising the further step of removing said release sheet andseparating it from said thick bitumen layer before placing saidbituminous roofing sheet onto the upper surface of said boards.
 10. Aprocess as claimed in claim 1, wherein said first and second sheets arenon-woven glass fabrics.
 11. A process as claimed in claim 1, whereinsaid first and second sheets are non-woven glass fabrics and saidthermal insulating layer consists essentially of rigid polyurethanefoam, said first sheet being impregnated with bitumen in such a mannerthat the bitumen does not exude to the lower surface thereof, wherebysaid rigid polyurethane foam is bonded through said lower surface ofsaid first sheet to said modified bitumen layer.
 12. A process asclaimed in claim 1, wherein a bitumen or rubberized bitumen coatinglayer is coated onto said upper surface of said second flat sheet, and arelease sheet is laminated on the upper surface of said coating layer.13. A process as claimed in claim 1, wherein a bitumen or rubberizedbitumen coating layer is coated onto said upper surface of said secondflat sheet, and mineral granules, powder or flakes are deposited on theupper surface of said coating layer.
 14. A process as claimed in claim1, in which said modified bitumen layer has a thickness of from 5 to 10mm and said inorganic filler is selected from the group consisting ofcalcium carbonate, clay, talc, aluminum hydroxide, mica, silica,graphite, carbon black, sand, fine gravel, crushed stone, asbestos,glass fibers, rock wool and mixtures thereof.
 15. A process as claimedin claim 14, in which said thermal insulating layer is made of amaterial selected from the group consisting of rock wool, slag wool,asbestos, glass fiber, foamed glass, foamed polystyrene, foamedpolyethylene, foamed acrylic resin, foamed phenol resin, foamed urearesin, foamed epoxy resin, foamed diallylphthalate resin, foamedpolyurethane resin, foamed rubber and wood chipboard.
 16. A process asclaimed in claim 15, wherein each of said boards have been prepared byshaping a composition in which said bitumen is molten to form saidmodified bitumen layer, laminating said first and second sheets bypressing same against the opposite surfaces of said modified bitumenlayer, and then applying said thermal insulating layer onto said firstsheet.